A 75-year-old woman presents to the clinic and discloses that since the last three months, she feels confused at times and feels like she must sit down. She says there is no vertigo or room spinning. She occasionally feels faint and has fallen four times. However, she is not sure of a blackout. The episodes last for 15–20 min and they go off on their own accord. She occasionally experiences palpitations followed by a feeling of faintness, with no chest pain, nausea or sweating. Physical examination She appears pale with almost normal breathing and is able to talk in complete sentences.

Her pulse is intermittently irregular with a rate of 132 bpm and BP is 100/80 mmHg. Her apex rate is 152 bpm, with no discernable murmurs. She has bilateral crackles in her lung bases. An electrocardiogram was carried out (Cover Image). What is the diagnosis and the progressive complication? (Answer is…